Question

3

"Can't check signature: public key not found" while upgrading, why?

rated 0 times [ 3] [ 0] / answers: 1 / hits: 9725 / 2 Years ago, thu, june 9, 2022, 2:08:35

I want to upgrade my Ubuntu 13.04 to Ubuntu 13.10. I'm unable to do via GUI.

[ The reason why I'm unable to do so:

Via software updater, I proceed ahead and click upgrade (for upgrading my OS). I authenticate by providing my password. Then it proceeds and downloads upgrade tool. That time only (while downloading the tool) error message comes "system program problem detected". It then doesn't proceed ahead and I click to report the problem ]

So, I tried via command line but here also I couldn't succeed upgrading my OS.
For the same I ran

$ sudo apt-get update

Then I ran

$ sudo apt-get dist-upgrade

And then:

ravbholua@ravbholua-Aspire-5315:~$ sudo do-release-upgrade

Checking for a new Ubuntu release

Get:1 Upgrade tool signature [198 B]                                                                                                 

Get:2 Upgrade tool [1,135 kB]                                                                                                        

Fetched 1,135 kB in 6s (32.9 kB/s)                                                                                                   

authenticate 'saucy.tar.gz' against 'saucy.tar.gz.gpg' 

gpg exited 2

Debug information: 





gpg: Signature made Friday 01 November 2013 10:34:27 AM IST using DSA key ID 437D05B5

gpg: Can't check signature: public key not found



Authentication failed

Authenticating the upgrade failed. There may be a problem with the network or with the server. 

ravbholua@ravbholua-Aspire-5315:~$

Please suggest how to go ahead and upgrade my OS.

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alliulet

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answered 2 Years ago diket · Accepted Answer

Try this:

gpg --keyserver keyserver.ubuntu.com --recv 437D05B5

apt-get update

Otherwise you might be able to use this blogpost:

The solution

After a bit of head scratching, it seems the simple solution is to delete all of the GPG keys in /etc/apt and re-run apt-get update.
cd /etc/apt

sudo mkdir gpgbackup

sudo mv *.gpg gpgbackup/

gpg --export -a 437D05B5 | sudo apt-key add -

sudo apt-get update

(added backing up instead of plain rm)